{"id":2225192,"url":"http://patchwork.ozlabs.org/api/1.1/patches/2225192/?format=json","web_url":"http://patchwork.ozlabs.org/project/linux-cifs-client/patch/20260420135058.469990-1-michael.bommarito@gmail.com/","project":{"id":12,"url":"http://patchwork.ozlabs.org/api/1.1/projects/12/?format=json","name":"Linux CIFS Client","link_name":"linux-cifs-client","list_id":"linux-cifs.vger.kernel.org","list_email":"linux-cifs@vger.kernel.org","web_url":"","scm_url":"","webscm_url":""},"msgid":"<20260420135058.469990-1-michael.bommarito@gmail.com>","date":"2026-04-20T13:50:58","name":"smb: client: require a full NFS mode SID before reading mode bits","commit_ref":null,"pull_url":null,"state":"new","archived":false,"hash":"24e3bb6775a10500766ce80b86ddf0483c1682d7","submitter":{"id":93078,"url":"http://patchwork.ozlabs.org/api/1.1/people/93078/?format=json","name":"Michael Bommarito","email":"michael.bommarito@gmail.com"},"delegate":null,"mbox":"http://patchwork.ozlabs.org/project/linux-cifs-client/patch/20260420135058.469990-1-michael.bommarito@gmail.com/mbox/","series":[{"id":500620,"url":"http://patchwork.ozlabs.org/api/1.1/series/500620/?format=json","web_url":"http://patchwork.ozlabs.org/project/linux-cifs-client/list/?series=500620","date":"2026-04-20T13:50:58","name":"smb: client: require a full NFS mode SID before reading mode bits","version":1,"mbox":"http://patchwork.ozlabs.org/series/500620/mbox/"}],"comments":"http://patchwork.ozlabs.org/api/patches/2225192/comments/","check":"pending","checks":"http://patchwork.ozlabs.org/api/patches/2225192/checks/","tags":{},"headers":{"Return-Path":"\n ","X-Original-To":["incoming@patchwork.ozlabs.org","linux-cifs@vger.kernel.org"],"Delivered-To":"patchwork-incoming@legolas.ozlabs.org","Authentication-Results":["legolas.ozlabs.org;\n\tdkim=pass (2048-bit key;\n unprotected) header.d=gmail.com header.i=@gmail.com header.a=rsa-sha256\n header.s=20251104 header.b=eX1CBI0I;\n\tdkim-atps=neutral","legolas.ozlabs.org;\n spf=pass (sender SPF authorized) smtp.mailfrom=vger.kernel.org\n (client-ip=2600:3c0a:e001:db::12fc:5321; helo=sea.lore.kernel.org;\n envelope-from=linux-cifs+bounces-10940-incoming=patchwork.ozlabs.org@vger.kernel.org;\n receiver=patchwork.ozlabs.org)","smtp.subspace.kernel.org;\n\tdkim=pass (2048-bit key) header.d=gmail.com header.i=@gmail.com\n header.b=\"eX1CBI0I\"","smtp.subspace.kernel.org;\n arc=none smtp.client-ip=209.85.222.175","smtp.subspace.kernel.org;\n dmarc=pass (p=none dis=none) header.from=gmail.com","smtp.subspace.kernel.org;\n spf=pass smtp.mailfrom=gmail.com"],"Received":["from sea.lore.kernel.org (sea.lore.kernel.org\n [IPv6:2600:3c0a:e001:db::12fc:5321])\n\t(using TLSv1.3 with cipher TLS_AES_256_GCM_SHA384 (256/256 bits)\n\t key-exchange x25519)\n\t(No client certificate requested)\n\tby legolas.ozlabs.org (Postfix) with ESMTPS id 4fzptQ21nFz1yCv\n\tfor ; Tue, 21 Apr 2026 01:14:22 +1000 (AEST)","from smtp.subspace.kernel.org (conduit.subspace.kernel.org\n [100.90.174.1])\n\tby sea.lore.kernel.org (Postfix) with ESMTP id E79A6361523E\n\tfor ; Mon, 20 Apr 2026 14:46:37 +0000 (UTC)","from localhost.localdomain (localhost.localdomain [127.0.0.1])\n\tby smtp.subspace.kernel.org (Postfix) with ESMTP id 7C6A12E7621;\n\tMon, 20 Apr 2026 13:51:08 +0000 (UTC)","from mail-qk1-f175.google.com (mail-qk1-f175.google.com\n [209.85.222.175])\n\t(using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits))\n\t(No client certificate requested)\n\tby smtp.subspace.kernel.org (Postfix) with ESMTPS id 0A9582DCBE3\n\tfor ; Mon, 20 Apr 2026 13:51:03 +0000 (UTC)","by mail-qk1-f175.google.com with SMTP id\n af79cd13be357-8dfb9139008so199174785a.1\n for ;\n Mon, 20 Apr 2026 06:51:02 -0700 (PDT)","from server0 (c-68-48-65-54.hsd1.mi.comcast.net. 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A malicious server can return\nan ACE with num_subauth = 2 and sub_auth[] = {88, 3}, which still\nmatches sid_unix_NFS_mode and then drives the sub_auth[2] read four\nbytes past the end of the ACE.\n\nRequire num_subauth >= 3 before treating the ACE as an NFS mode SID.\nThis keeps the fix local to the special-SID mode path without changing\ncompare_sids() semantics for the rest of cifsacl.\n\nFixes: e2f8fbfb8d09 (\"cifs: get mode bits from special sid on stat\")\nCc: stable@vger.kernel.org\nAssisted-by: Claude:claude-opus-4-6\nSigned-off-by: Michael Bommarito \n---\n fs/smb/client/cifsacl.c | 1 +\n 1 file changed, 1 insertion(+)","diff":"diff --git a/fs/smb/client/cifsacl.c b/fs/smb/client/cifsacl.c\nindex c920039d733c..a62c8a733779 100644\n--- a/fs/smb/client/cifsacl.c\n+++ b/fs/smb/client/cifsacl.c\n@@ -831,6 +831,7 @@ static void parse_dacl(struct smb_acl *pdacl, char *end_of_acl,\n \t\t\tdump_ace(ppace[i], end_of_acl);\n #endif\n \t\t\tif (mode_from_special_sid &&\n+\t\t\t ppace[i]->sid.num_subauth >= 3 &&\n \t\t\t (compare_sids(&(ppace[i]->sid),\n \t\t\t\t\t &sid_unix_NFS_mode) == 0)) {\n \t\t\t\t/*\n","prefixes":[]}